Clinical and microbiological characterization of sepsis and evaluation of sepsis scores

Reliability of Droplet Digital PCR Alone and in Combination with Interleukin-6 and Procalcitonin for Prognosis of Bloodstream Infection

Purpose

Bloodstream infection(BSI) is linked with high mortality, underscoring the significance of prompt etiological diagnosis for timely and precise treatment. This study aims to investigate the diagnostic value of droplet digital polymerase chain reaction(ddPCR) in combination with conventional inflammatory markers [interleukin-6(IL-6) and procalcitonin(PCT)] concerning disease progression and treatment prognosis in BSI patients. Furthermore, the study aims to explore a more efficient clinical application strategy.

Patients and Methods

This prospective case seried study centers on 176 patients suspected of or confirmed with BSI. Blood samples were collected to extract nucleic acids for identifying pathogens (bacteria, fungi, and viruses) and determining copy loads via ddPCR.

Results

The sensitivity of ddPCR was markedly higher compared to the culture method (74.71% vs 31.03%). A positive correlation existed between bacterial load and levels of inflammatory markers [IL-6 (P=0.0182), PCT (P=0.0029), and CRP (P=0.0005)]. In suspected BSI cases, the combination of ddPCR and inflammatory markers could predict sepsis risk [ROC: Area under the curve(AUC)=0.6071, P=0.0383]. Within confirmed BSI patients, the ddPCR bacterial load of those with SOFA<7 was lower than that of the SOFA≥7 (P=0.0334). ddPCR (OR: 1.789, P=0.035) monitoring combined with PCT (OR: 1.787, P=0.035) holded predictive value for SOFA progression (AUC=0.7913, P=0.0003). Similarly, BSI survivors displayed a lower burden than non-survivors (P=0.0170). Additionally, ddPCR combinated with IL-6 provided a more accurate and expedited insight into clinical outcomes prediction for BSI confirmed patients (AUC=0.7352, P=0.0030). Serial monitoring of bacterial load by ddPCR effectively mirrored the clinical course of BSI in patients. Notably, patients with positive ddPCR virus infection exhibited significantly reduced lymphocyte counts (P=0.0003).

Conclusion

In a clinical context, qualitative ddPCR results and quantitative continuous monitoring can more precisely assess sepsis progression and treatment prognosis in BSI patients. Furthermore, ddPCR results offer quicker and more accurate reference points for clinical antibacterial and antiviral interventions.

Prevalence and mortality rate of sepsis among adults admitted to hospitals in sub-Saharan Africa: a systematic review and meta-analysis

Due to abundant pathogen diversity and mounting antimicrobial resistance, sepsis is more common in sub-Saharan Africa (sSA). However, there is a lack of consistent reports regarding the prevalence of adult sepsis in the region. Therefore, this study aimed to determine pooled estimates of sepsis prevalence and associated mortality among adults admitted to hospitals in sSA. Medline (through PubMed), Scopus, Embase, and Web of Science were systematically searched for studies of sepsis in sSA published before 13th February 2023. A random-effects meta-analysis of hospital-wide and intensive care unit (ICU)-based sepsis prevalence was performed with a 95% confidence interval (CI). Subgroup analysis was conducted considering geographic region and sepsis diagnostic criteria. Funnel plots and Egger's test were used to assess publication bias. The protocol was submitted to the Prospective Register for Systematic Reviews (PROSPERO) with an identifier (CRD42023396719). Overall, 14 observational studies, published between 2009 and 2022, from eight different sSA countries comprising 31,653 adult patients (5723 with sepsis) were included in the review. Nine studies that were conducted in a hospital-wide setting showed a pooled prevalence and mortality of 17% (95% CI: 12-21%) and 15% (95% CI: 17-35%), respectively. Five studies in the ICUs presented a pooled prevalence and mortality of 31% (95% CI: 24-38%) and 46% (95% CI: 39-54%), respectively. Based on the sub-group analysis, the pooled hospital-wide prevalence of sepsis in East and Southern Africa was 18% (95% CI: 11-25%), and 20% (95% CI: 2-42%), respectively. The pooled prevalence in the ICU was 14% (95% CI: 4-23%) and 13% (95% CI: 5-20%) for East and Southern Africa, respectively. The hospital-wide and ICU-based sepsis prevalence and mortality are high in sSA. Addressing the burden of adult sepsis should be a priority for healthcare systems in sub-Saharan Africa.

Prediction of unfavorable outcomes in community-acquired bacteremia by SIRS, SOFA and qSOFA scores

BACKGROUND

Sepsis diagnostic and prognostic scoring systems have changed over time. It remains uncertain which scoring system is the best predictor of unfavorable outcomes. We aimed to evaluate prediction of community-acquired bacteremia (CAB) outcomes using on-admission systemic inflammatory response syndrome (SIRS), sequential organ failure assessment (SOFA) and quick sequential organ failure assessment (qSOFA).

METHODS

We present a retrospective observational cohort study of consecutive adult patients hospitalized with CAB over ten years. SIRS, qSOFA and SOFA scores calculated on admission were dichotomized as ≥2 or 0-1. Raw and adjusted incidence of a composite unfavorable outcome (death, septic shock, invasive mechanical ventilation, extra-corporeal membrane oxygenation, renal replacement therapy) over 35 days were compared.

RESULTS

Among 1930 patients, 1221 (63.3%) had SIRS, 196 (10.2%) had qSOFA, and 1117 (57.9%) had SOFA≥2. Respective raw and adjusted probabilities of the outcome were similar. Incidence for qSOFA≥2 was high (41.3%) and still considerable for qSOFA 0-1 (5.4%). SOFA≥2 indicated higher risk than SIRS≥2 (14.7% vs. 12.4%), while SOFA 0-1 indicated lower risk than SIRS 0-1 (1.2% vs. 3.1%). This relationship between SOFA and SIRS was also observed in patients with qSOFA 0-1.

CONCLUSIONS

qSOFA≥2 was associated with highest probability of unfavorable outcome, but dichotomized SOFA was more precise at high vs. low-risk distinction. Consecutive use of dichotomized qSOFA and SOFA on admission of adults with CAB enables fast and reliable identification of patients at high (qSOFA≥2, risk ~≥35%), moderate (qSOFA 0-1, SOFA≥2, risk ~10%), and low risk (qSOFA 0-1, SOFA 0-1, risk 1-2%) of subsequent unfavorable events.

Detection of Inflammatory Biomarkers Among Patients with Sepsis of Gram-Negative Bacteria: A Cross-Sectional Study

Background

Sepsis is a highly mixed ailment that affects patients with numerous conditions of infectious sources and can lead to multi-organ failure with dysregulated host immune response.

Objective

To determine inflammatory biomarkers in patients with sepsis caused by Gram-negative bacteria and compare their role in the early detection of sepsis.

Methods

This cross-sectional study was conducted on patients with sepsis admitted to the intensive care unit at different hospitals in Sulaimaniyah, Iraq, from May to December 2021. Patients (n=147) were enrolled in this study according to the primary diagnosis of sepsis by Sequential Organ Failure Assessment scores. Blood samples were taken from patients to investigate white blood cells, inflammatory biomarkers (pentraxin-3, procalcitonin, adrenomedullin, lipopolysaccharide binding protein, interleukin-17A, lactate dehydrogenase, and C-creative protein), blood culture, antibiotic susceptibility test, and coagulation biomarkers (Prothrombin time, activated partial thromboplastin time, and international normalized ratio). Then, isolated Gram-negative bacteria were tested for extended-spectrum β-lactamase enzymes production by screening and combined disc tests.

Results

A total of 51.7% samples were blood culture positive for different Gram-negative bacteria, and P. aeruginosa (51.95%) was a more isolated bacterium. Both males and females were affected by sepsis in a ratio of 1.23:1 with different age groups. Extended-spectrum β-lactamase was estimated to be 77.2% by antibiotic profile, and the rate decreased using two double-disc synergy tests. This was confirmed by combined disc test at a rate of 41.35%. The most prevalent biomarkers were procalcitonin (88.16%), adrenomedullin (84.21%), pentraxin-3 (22.37%), and lipopolysaccharide binding protein (11.84%).

Conclusion

Sepsis is a life-threatening condition that can be diagnosed early by several blood biomarkers such as procalcitonin, adrenomedullin, and pentraxin-3 combined with a standard blood culture technique to improve the patient outcome.

Disseminated Cryptococcosis Is a Common Finding among Human Immunodeficiency Virus-Infected Patients with Suspected Sepsis and Is Associated with Higher Mortality Rates

Cryptococcosis is the leading cause of death among people with HIV in Sub-Saharan Africa. The lack of optimum diagnoses and medications significantly impair the management of the disease. We investigated the burden of cryptococcosis and related mortality among people with HIV and suspected sepsis in Ethiopia. We conducted a prospective study at (1) Adama Hospital Medical College and (2) Asella Referral and Teaching Hospital from September 2019 to November 2020. We enrolled adult, HIV-infected patients presenting with suspected sepsis and assessed their 28-day survival rates. We performed blood cultures and cryptococcal antigen (CrAg) testing. In total, 82 participants were enrolled with a median age of 35 years, and 61% were female. Overall, eleven (13%) had positive CrAg tests, of which five grew Cryptococcus in blood cultures. Despite high-dose fluconazole (1200 mg/d) monotherapy being given to those with positive CrAg tests, the 28-day mortality was 64% (7/11), with mortality being significantly higher than among the CrAg-negative patients (9% (6/71); p < 0.001). Cryptococcosis was the leading cause of mortality among HIV-infected sepsis patients in this Ethiopian cohort. The CrAg screening of HIV-infected patients attending an emergency department can minimize the number of missed cryptococcosis cases irrespective of the CD4 T cell count and viral load. These findings warrant the need for a bundle approach for the diagnosis of HIV-infected persons presenting with sepsis in low- and middle-income countries.

Reduction of BSI associated mortality after a sepsis project implementation in the ER of a tertiary referral hospital

The emergency room (ER) is the first gateway for patients with sepsis to inpatient units, and identifying best practices and benchmarks to be applied in this setting might crucially result in better patient's outcomes. In this study, we want to evaluate the results in terms of decreased the in-hospital mortality of patients with sepsis of a Sepsis Project developed in the ER. All patients admitted to the ER of our Hospital from the 1st January, 2016 to the 31stJuly 2019 with suspect of sepsis (MEWS score ≥ of 3) and positive blood culture upon ER admission were included in this retrospective observational study. The study comprises of two periods: Period A: From the 1st Jan 2016 to the 31st Dec 2017, before the implementation of the Sepsis project. Period B: From the 1st Jan 2018 to the 31stJul 2019, after the implementation of the Sepsis project. To analyze the difference in mortality between the two periods, a univariate and multivariate logistic regression was used. The risk of in-hospital mortality was expressed as an odds ratio (OR) and a 95% confidence interval (95% CI). Overall, 722 patients admitted in ER had positive BC on admissions, 408 in period A and 314 in period B. In-hospital mortality was 18.9% in period A and 12.7% in period B (p = 0.03). At multivariable analysis, mortality was still reduced in period B compared to period A (OR 0.64, 95% CI 0.41-0.98; p = 0.045). Having an infection due to GP bacteria or polymicrobial was associated with an increased risk of death, as it was having a neoplasm or diabetes. A marked reduction in in-hospital mortality of patients with documented BSI associated with signs or symptoms of sepsis after the implementation of a sepsis project based on the application of sepsis bundles in the ER.

Prevalence and characterization of antimicrobial resistance among gram-negative bacteria isolated from febrile hospitalized patients in central Ethiopia

BACKGROUND

Infectious diseases are among the leading causes of death in many low-income countries, such as Ethiopia. Without reliable local data concerning causative pathogens and antimicrobial resistance, empiric treatment is suboptimal. The objective of this study was to characterize gram-negative bacteria (GNB) as pathogens and their resistance pattern in hospitalized patients with infections in central Ethiopia.

METHODS

Patients ≥ 1 year of age with fever admitted to the Asella Referral and Teaching Hospital from April 2016 to June 2018 were included. Blood and other appropriate clinical specimens were collected and cultured on appropriate media. Antibiotic susceptibility testing (AST) was performed using the Kirby-Bauer method and VITEK® 2. Species identification and detection of resistance genes were conducted using MALDI-ToF MS (VITEK® MS) and PCR, respectively.

RESULTS

Among the 684 study participants, 54.2% were male, and the median age was 22.0 (IQR: 14-35) years. Blood cultures were positive in 5.4% (n = 37) of cases. Among other clinical samples, 60.6% (20/33), 20.8% (5/24), and 37.5% (3/8) of swabs/pus, urine and other body fluid cultures, respectively, were positive. Among 66 pathogenic isolates, 57.6% (n = 38) were GNB, 39.4% (n = 26) were gram-positive, and 3.0% (n = 2) were Candida species. Among the isolated GNB, 42.1% (16/38) were Escherichia coli, 23.7% (9/38) Klebsiella pneumoniae and 10.5% (4/38) Pseudomonas aeruginosa. In total, 27/38 gram-negative isolates were available for further analysis. Resistance rates were as follows: ampicillin/sulbactam, 92.6% (n = 25); cefotaxime, 88.9% (n = 24); ceftazidime, 74.1% (n = 20); cefepime, 74.1% (n = 20); gentamicin, 55.6% (n = 15); piperacillin/tazobactam, 48.1% (n = 13); meropenem, 7.4% (n = 2); and amikacin, 3.7% (n = 1). The bla_NDM-1 gene was detected in one K. pneumoniae and one Acinetobacter baumannii isolate, which carried an additional bla_OXA-51 gene. The ESBL enzymes were detected in 81.5% (n = 22) of isolates as follows: TEM, 77.2% (n = 17); CTX-M-1 group, 68.2% (n = 15); SHV group, 27.3% (n = 6); and CTX-M-9 group, 9.1% (n = 2). Based on the in vitro antimicrobial susceptibility results, empiric treatment initiated in 13 of 18 (72.2%) patients was likely ineffective.

CONCLUSION

We report a high prevalence of ESBL-producing bacteria (81.5%) and carbapenem resistance (7.4%), with more than half of GNB carrying two or more ESBL enzymes resulting in suboptimal empiric antibiotic therapy. These findings indicate a need for local and national antimicrobial resistance surveillance and the strengthening of antimicrobial stewardship programs.